Glycopyrrolate is a quaternary ammonium cation of the muscarinic anticholinergic group. Glycopyrrolate, typically as a bromide salt, has been used in the treatment of a variety of conditions including diarrhea (U.S. Pat. Nos. 6,214,792 and 5,919,760), urinary incontinence (U.S. Pat. Nos. 6,204,285 and 6,063,808), and anxiety (U.S. Pat. No. 5,525,347). Additionally, U.S. Pat. No. 5,976,499 discloses a method for diagnosing cystic fibrosis in a patient by, in part, stimulating sweat production through the injection of a glycopyrrolate solution into a patient. Glycopyrrolate has also been used for the treatment of hyperhidrosis in US 20100276329.
Hyperhidrosis affects 8.8 million individuals in the United States alone, of whom 50.8% are estimated to have axillary hyperhidrosis and 25-34% have palmar or plantar hyperhidrosis. Hyperhidrosis is often treated with aluminum salts. Applying aluminum salts, such as aluminum chloride, causes frequent skin irritation and is of only limited effectiveness. Topically applied glycopyrrolate bromide has been shown to cause less skin irritation and have increased effectiveness over aluminum chloride.
Glycopyrrolate has well-known pharmacology (anticholinergic) and acts as a muscarinic receptor antagonist. As with other anticholinergic agents, glycopyrrolate inhibits the action of acetylcholine on structures innervated by postganglionic cholinergic nerves, such as sweat glands. Under physiologic conditions, salts of glycopyrrolate are dissociated; therefore, the pharmacological activity of glycopyrrolate is mediated by the active cation moiety, also referred to as glycopyrronium.
Glycopyrrolate has previously been made available as a bromide salt or an acetate salt. The bromide salt of glycopyrrolate is sold as Rubinol®. The term “glycopyrrolate” as used in the label for Rubinol® refers to the bromide salt which is more formally referred to as glycopyrronium bromide.
A drawback of using bromide salts of pharmaceutical compounds is the potential for inducing bromism which can result from too high an intake of bromide. Symptoms of bromism may include neurological abnormalities such as vision impairment and upper motor neuron disorders and dermatologic conditions such as papular and macular rashes. Symptoms more often develop due to chronic use rather than acute toxicity.